<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <title>Document</title>
  <style>
    
  </style>
</head>
<body>
  
</body>
<script>

  // var obj = {name:"Admin"}
  // console.log( obj );
  // console.log( obj + 1 )

  // var str = new String("hello");
  // console.log(str);
  // console.log(typeof str);  // object

  // // 但是：可以作为正常字符使用

  // console.log( str + 1 )

  // var num = new Number(123);
  // console.log(num)
  // console.log(typeof num)

  // console.log( num + 1 )




  // var str1 = "hello";
  // var str2 = "hello";
  // var str3 = new String("hello");
  // var str4 = new String("hello");

  // console.log( str1 === str2 );
  // console.log( str3 === str4 );

  // var str5 = str4;

  // console.log(str5 === str4);
  
  // // 任何两个 复杂数据 都不相等；只要相等了，就必然是同一个数据

  // console.log( "" === "" );
  // console.log( "hello" === "hello" );

  // console.log( {} === {} );
  // console.log( [] === [] );
  // console.log( function(){} === function(){} );










  function fn(){

    console.log("fn被执行了")

  }

  console.log( fn );

  console.log( fn() );

  console.log( new fn );
  



</script>
</html>